Apparatus for treating hydrocarbons



Feb. 20, 1934.

HMAGNUS APPARATUS FOR TREATING HYDROCARBONS Filed March l2 1929 2 Sheets-Sheet 1 NMIZUDZOU vMWI-buia) .U2-14000 wuon. wummazoo 1:0 STM Feb. 2o, 1934. H. MAGNUS 1,948,072

APPARATUS FOR TREATING HYDROCARBONS Filed March l2, 1929 2 Sheets-Sheet 2 Petenred Feb.2o, 1934 APPARATUS FOR TRETING HYDBOCARBONS Hans Magnus, Au, near Freiburg, Germany Application March 12,

and in Germany March 10,

1929, serial No. 346,319,

z claims. (ci. 19e-132) My invention refers to means for treating hydrocarbons and more especially to apparatus adapted for use in cracking heavy hydro-carbons at high temperature either in tubes or in I a metal bath. It is an object of my invention to provide means for preventing the deposition of coke on the inner walls of the apparatus.

Hitherto, in order to limit the decomposition of carbon and the formation of coke, the raw material to be cracked was passed through the heating zone'at high velocity, thereby providing that the carbon was deposited only in the succeeding zones of reactionpfrom which it could be removed more readily. However this mode of proceeding ds not avoid local overheating and besides very high losses of pressure in the heating zone are experienced.

I avoid these drawbacks according to the present invention by regulating the temperature and keeping it constant by means of regulatingA devices, which control the passage of the oil through the heating zone in dependency from the temperature prevailing therein. 'As compared with the well known regulation of the temperature in the furnace, the regulation of the quantity and temperature of the oil entering the apparatus involves the advantage of temporary action, while if the heat of the furnace is regulated4 that part of the heat, which is accumulated in the brickwork, will still remain active for some time so that local overheating cannot be prevented.

I also succeed in preventing the deposition of carbon by reversing the direction of flow within the heating tubes, thereby creating eddies and causing the carbon to assume colloidal form, so that it cannot deposit in solid form.

In order to prevent overcracking I separate out the light oils produced during the cracking in a prevaporizer before the heated material is introduced into the reaction zone, in which it is subjected to final cracking during suflicient time. I thus succeed in preventing the petrol, which has already been formed in the preliminary cracking zone, from being decomposed in the final reaction zone.

In the drawings amxed to the specication and forming part thereof, apparatus embodying my invention are illustrated diagrammatically by way of example. In the drawings plant embodying Fiss. 2 and 3 are a my invention as a whole, while longitudinal section and end view, respectively, of the cracking tubes,

and l Figs; 4 and 5 are vertical sections of two different forms of cracking arrangements including a metalv bath.

Referring first to Fig. 1 of the drawings, 1 is a tank containing the raw oil and 2 is a pump which sucks the oil from tank 1 and forces it through a preheate into the hot oil tank 4. 5 is a pump which forces the hot oil from the tank 4 into the tubes 6, in which the oil is heated to cracking temperature. A by-pass pipe 7 allows supplying the pump 5 directly with fresh oil. The proper mixture of hot and fresh oil is` controlled by valves 8 and 9, which are influenced by a 'thermostatl arranged in the cracking zone in such manner that, if the temperature rises above a predetermined limit, the

valve 9 is opened to admit more fresh oil, while, y

if necessary, valve 8 is partially closed to reduce the supply of hot oil. The thermostat may also be arranged to act through valve 11 onto the supply of fuel to the burner 12.

From the heating cracking zoneV into the prevaporizer 13, in which it ows down on a corrugated surface 14 in order that .the light petrol vapors be separated oi, which escape through the safety valve 17 provided with the counter weight 18 and pipe 19 to 'the condensers 20, 21, where petrol can be withdrawn by means of the cocks 22, 23.

That part of the liquid, which is not vaporized in the vaporizer 13, iiows from the collecting tank through pump 16 and the open valve 24 (valve 25 being closed) through the heating and cracking zone 25 and through pipe 27 into the reaction cracking zone 28, where, owing to the reduced velocity of flow, the oil remains for some time ,as required by the cracking reaction. At 29 heavy residues, which have separated out may be withdrawn while the main portion of the liquid ows through pipe 30 and valve 31 into the vaporizer 32, in which spontaneous vaporization takes place. Any residues which do not undergo vaporization can be withdrawn through cock 33 or can be returned through valve 34 and pipe 35 to the pump 2 or may be fed into the burner.

The vapors from the vaporizer 32 pass into i the condenser 36 for fractional condensation. Here the heaviest condensation products separate out in the bottom part and may be withdrawn at 37 or may be returned through valve 49 and pipe 43 to the pump 2. In the part of the condenser 36. which is air-cooled by meam larger scale in Figs. 2 and 3.

through pipe 46,- can be condensed in thepetrol condensersv 20, 21, through which passes cold cooling water entering through'pipe 47 and escaping through coiled pipe 45, 48. Owing to this arrangement the cooling temperature in the uppermost part of condenser 36 is higher than the temperature in the condensers 20, 21.

Float valves 49, 50 in the prevaporizer 13 pre- Y vent liquid from entering the vapor pipe 19 if the level is too high, and vaporfrom entering the pump 16 if the level should be too low.

The cracking tubes 6 are illustrated on a 'Ihe liquid is shown to enter the upper tube 6 in counter cur- `rent to the heating gases and after having passed the inner tubes 51 has its direction of flow reversed near the end of the outer tube 52, passing through the connecting pipe 55 and entering the next following inner tube 51. Owing to this arrangement the transmission of heat from theheating gases to the oil takes place only while the oil is flowing with greater velocity through the outer tubes `52, while'during the slower ow in the tubes 51 heat is transmitted only from the oil in the outer tube 52' to the oil in the inner tube 51. .Thestoppers 53, 54

can be withdrawn if it is desired -to clean the tubes. The tubes 51 are positioned within the tubes y52 by means of ribs 56,' which may have a helical form in order to effect a thorough mixture of the oil flowing between the ribs. The cross sectional areas are so chosen that the cross sectional area of the tubes 51 is more than one half of the cross sectional area of the tubes 52, thereby providing that the velocity of now between the tubes is greater-than that in the inner tubes 51.

In the modification illustrated in Fig. 4 the tubes 6 yare replaced by a cracking vessel 58,

which may be filled with a body of molten metal 59 serving to transmit heat to the oil. From the' tank 4 in which the oil is preheated in the preheater 3, the pump 5 forces oil through valve 8 into the coil 57 arranged in the container 58.

The thermostat 10 arranged in the molten metal 59 controls the feed of hot oil through valve 8 and of cold oil through valve 9 in such manner that if a predetermined temperature is overstepped the quantity of 'cold oil is increased while the quantity of hot oil is reduced.

In the modification illustrated in Fig. 5 a coil `63 supplied with' fresh oil through pipe 60 and Va1ve, 61 is arranged in the cracking vessel 58.

y The il passing through this coil is preheated therein and allowed to flow into the hot oil tank 4 from which it is forced by pump 5 throughl valve 62 into the container 58 to be subjected to cracking therein. The thermostat 10 controls the ow of the oil acting as a cooling medium through valve 61 and coil 63.

The hot oil tank 4 serves for equalizlng the supply of preheated oil, which is required according to Figs. 1 and 4 by the circumstance that the withdrawal of hot oil varies lin accordance with the regulation of valve 8 while according toy Fig. 5 the provision of hot oil varies according to the regulation of valve 61.

Instead of regulating the cold and hot oil feeds it may also prove sucient to regulate the passage of the oil across the cracking zone in such manner that the quantity of oil passing through is increased whenever the highest admissible temperature is overstepped.

The regulating valves are influenced by the thermostat by means of compressed air, pressure liquid or by electrical means in order that, although the thermostat, only exerts very small forces, comparatively great forces can be exerted on the valves in order to enable them to overcome'all resistances which may be offered .by coke deposited within the valves.

Various changes may be made in the details disclosed in the foregoing specification withoutV departing from the invention or sacrificing the advantages thereof.

I claimz l. An apparatus for treating hydrocarbons comprising an 'oil reservoir, a preheating coil, a cracking coil, a-directv pipe leading from said resevoir to said cracking coil, another pipe leading from said reservoir to the preheating coil and from here into said direct pipe, valves in both pipes, a pump in the pipe between the juncture of the direct pipe with the pipe carrying the pre-heated oil and thecracking coil, and means for regulating the operative position of said -valves in dependency upon the temperature in the cracking coil to increase theow through said direct pipe when the temperature in the cracking eoil rises, vand to reduce the flowA through said direct pipe` if the temperature in the cracking coil drops.

2.' An apparatus for treating hydrocarbons comprising an oil reservoir; a preheating coil, a

cracking coil, a direct pipe leading from said reservoir to said cracking coil, another pipe leading from said reservoir to the preheating coil and from here into said direct pipe, valves in both pipes, a pump in the pipe betweenfthe juncture of the direct pipe with the pipe carrying the preheated oil and the cracking l:coil means for regulating the operative position of said valves in dependency upon the temperature in the cracking coil to'increase the flow through said direct pipe when the temperature in the crack-- ing coil rises, and to reduce the flow `through said direct pipefif the temperature in the cracking coil drops, and a vessel for preheated material'being inserted in said other pipe-to the rear of said preheatingy coil, said vessel serving, for balancing the difference between the supply of preheated oil to and the withdrawal of such oil from said cracking coil.

HANS MAGNUS. 

